Re: [PATCH v1 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC

[Ramuthevar, Vadivel MuruganX]

Hi Boris,

On 17/4/2020 3:02 pm, Boris Brezillon wrote:
> On Fri, 17 Apr 2020 13:21:39 +0800
> "Ramuthevar, Vadivel MuruganX"
> <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote:
>
> > Hi Boris,
> >
> > On 16/4/2020 7:57 pm, Boris Brezillon wrote:
> > > On Thu, 16 Apr 2020 19:38:03 +0800
> > > "Ramuthevar, Vadivel MuruganX"
> > > <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote:
> > >   
> > > > On 16/4/2020 7:17 pm, Boris Brezillon wrote:
> > > > > On Thu, 16 Apr 2020 18:40:53 +0800
> > > > > "Ramuthevar, Vadivel MuruganX"
> > > > > <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote:
> > > > >      
> > > > > > > > > we'll be happy to have one more of the existing driver converted to
> > > > > > > > > ->exec_op() ;-).
> > > > > > > > I have completely adapted to ->exec_op() hook up to replace the legacy
> > > > > > > > call-back.
> > > > > > > I suspect porting what you've done to the xway driver shouldn't be too
> > > > > > > complicated.
> > > > > > Not ported from xway_nand.c driver , we have developed from the scratch
> > > > > > to make it work on
> > > > > > Intel LGM SoC , it's new x86 ATOM based SoC, IP itself completely
> > > > > > different and most of the registers won't match.
> > > > > > if we port then it would be ugly and also what are the problem may occur
> > > > > > we do not know.
> > > > > Sorry but IMO they look similar enough to try to merge them.
> > > > Thanks! Boris, need suggestion from you since you are maintainer and
> > > > also expertise on mtd-subsystem.
> > > I *was* the maintainer :).
> > >   
> > > > There are different features involved and lines of code is more, if we
> > > > add new driver patches over xway-nand driver
> > > How about retro-fitting the xway logic into your driver then? I mean,
> > > adding a 100 lines of code to your driver to get rid of the 500+ lines
> > > we have in xway_nand.c is still a win.
> > >   
> > > > is completely looks ugly and it may disturb the existing functionality
> > > > as well since we don't have platform to validate:'(.
> > > How ugly? Can you show us? Maybe we can come with a solution to make it
> > > less ugly.
> > >
> > > As for the testing part, there are 4 scenarios:
> > >
> > > 1/ Your changes work perfectly fine on older platforms. Yay \o/!
> > > 2/ You break the xway driver and existing users notice it before this
> > >      series gets merged. Now you found someone to validate your changes.
> > > 3/ You break the xway driver and none of the existing users notice it
> > >      before the driver is merged, but they notice it afterwards. Too bad
> > >      this happened after we've merged the driver, but now you've found
> > >      someone to help you fix the problem :P.
> > > 4/ You break things for old platforms but no one ever complains about
> > >      it, either because there's no users left or because they never
> > >      update their kernels. In any case, that's no longer your problem.
> > >      Someone will remove those old platforms one day and get rid of the
> > >      unneeded code in the NAND driver.
> > >
> > > What's more likely to happen is #3 or #4, and I think the NAND
> > > maintainer would be fine with both.
> > >
> > > Note that the NAND subsystem is full of unmaintained legacy drivers, so
> > > every time we see someone who could help us get rid or update one of
> > > them we have to take this opportunity.
> > Agreed!, Thank you very much for the suggestions and clear inputs.
> > To proceed further, can you please share your inputs to dividing the tasks
> > and patches to be sent if possible.
> Let's start with the new version you were about to post. We'll see how
> we can merge both drivers based on that.

Thank you very much for the review comments and inputs , will post the 
patches soon.

Regards
Vadivel